Field
The description relates to a filter and a front end module including the same.
Description of Related Art
In accordance with the rapid development of mobile communications devices, chemical and biological devices, and the like, demand for small, light filters, oscillators, resonant elements, acoustic resonant mass sensors, and the like, used in such devices, has also increased.
As a member for implementing such small, light filters, oscillators, resonant elements, acoustic resonant mass sensors, and the like, a film bulk acoustic resonator (FBAR) has been used. Such a film bulk acoustic resonator may be mass-produced at low cost, and may be implemented to have subminiature size. In addition, the FBAR may have a high quality factor (Q) value, a main characteristic of a filter, implemented therein, may be used even in a microwave frequency band, and may allow for the use of particular bands of a personal communications system (PCS) and a digital cordless system (DCS).
Recently, as wireless terminals have been implemented with the ability to support communications within a plurality of bands, a plurality of filters controlling the plurality of bands have been used in the wireless terminals. However, when the number of filters controlling the plurality of bands is increased in accordance with the increase in the number of bands, a signal processing process may become complicated, while manufacturing costs and a size of a filter module may be increased.